Hi pythonmania, Thanks for many advices you've given in my previous problem [list comprehension]. Now, StraightToProblem: I have an object "Class_A" that get a big data from MySQL to do search/sort etc. How can I share that data, so that if other object "Class_B", "Class_C" need the same data, they can use it, without have to call it from MySQL. Best Regards, Nano'